Heating unit circuit breaker



R. J. PARSONS HEATING UNIT CIRCUIT BREAKER March 2, 1937.

Filed Dec. 19, 1933 INVENTOR 6 ATT o RNEY 2 A 3 5 n 1 L O n I/ 6 2 pm 25 H 4 x3 m A 7 0 1 4 I 1 1.. x 9 I, 1 A 2 8 9 9 l .1. 7. 3 I... O 4 1 Oifl5 Patented Mar. 2, 1937 HEATING UNIT CIRCUIT BREAKER Robert J.Parsons, Schenectady, N. Y., assignor to Consolidated Car HeatingCompany, Inc.,

Albany, N. Y., a corporation of New York Application December 19, 1933,Serial No. 703,041

9 Claims.

, This invention relates to electricity, particularly to electricheating, and more especially to the circuits and apparatus used therein.

acquainted with the art of electric heating, especially the heating ofelectrically propelled vehicles, are aware that the management is oftenin unskilled hands, and consequently the circuits and apparatusconnected therewith must be such that it is easily manipulated, ruggedin construction, easily maintained, and so designed that positiveassurance is secured that the electric current will not be allowed toflow through the heating units after the space in which they are placedreaches a certain temperature.

A principal object of the present invention is to provide a system ofcircuits for heating installations, and the necessary automatic circuitbreakers in connection therewith such that safety in use, easymanipulation, and the greatest degree of freedom from maintenancetroubles will be secured. Y

Qther objects and advantages will appear as the description of theparticular physical embodiment selected to illustrate the inventionprogresses and the novel features will be particularly pointed out inthe appended claims.

In describing the invention in detail and the particular physicalembodiment selected to illustrate the invention reference is had to theaccompanying drawing wherein like characters of reference designate likeparts throughout the several views, and in which:

Figure 1 is a front elevational view of a circuit breaker embodying myinvention; Fig. 2 is a side elevational view of the device as shown byFig. 1; Fig. 3 is a top plan view of the device as shown by Fig. 1; Fig.4 is a schematic view illustrating the connections andarrangement of thedevice, as shown by Figs. 1 to 3 inclusive, in connection 46 with aheating device.

The circuit breaker as shown by Figs. 1 to 3 inclusive, comprisesessentially a pivoted electrical conducting arm controllable bothmanually and electro-magnetically.

5 In- Fig. 1 the electric conducting arm is designated I. It is attachedin any suitable or appropriate manner, as by riveting, to the two armlever 2. The two arm lever 2 is pivoted in any suitable or appropriatemanner, as by pivot pin 5 3, supported by the extended arms 4 and 5. The

' pivot pin 3 is so placed that the conducting arm 1 I cooperates with astationary contact 6 when in one position, but is separated therefromwhen in another of its positions, as shown by dash lines inFig. 1.

The two arm lever 2 is provided with a latch engaging shoulder I and isadapted to cooperate with the shoulder 8 of a latch 9. When the shoulder1 of the two arm lever 2 cooperates, as shown in Fig. l, with theshoulder 8 of the latch 9, the conducting arm I is in cooperativerelation with the conducting contact 6. The two arm lever 2 alsocooperates with a. stop l0 which limits its movement in one direction.

The latch 9 is pivoted in any suitable or appropriate manner, as by thepivot pin ll supported by the outstanding bearings l2 and I3, so that itis free to oscillate. The latch 9 also carries a limiting shoulder I4which is positioned and adapted to limit the movement of the two armlever 2 in a direction away from the stop It) so that when the limitingshoulder l4 cooperates with the two arm lever 2 the conducting arm I isin the dash line position as shown in Fig. 1.

The stop I 0, the extended arms 4 and 5 and the extended arms l2 and I3are attached to a coil housing I5, preferably integral. This coilhousing I5 is made of metal preferably, a magnetic metal, which not onlyprotects and encloses a wire coil l5, but is attached to one end of amagnetic core l1, as by screw 18, thus forming part of the magneticcircuit of the electro-magnet having the coil IS.

A flange I8 extends from the lower end of the housing l5 and supportsheaded pins l9. These pins 19 in turn support the armature 20.

The energization of the coil l6 by electric current causes the armature20 to rise, as viewed in Fig. 1, and in so doing to lift the latch rod2|. This latch rod 2| is guided in bores 22 and 23 in the arms 5 andIll, and so positioned that when it rises it contacts with the latch 9and raises the latch. When the latch 9 is raised the shoulder 8 isremoved from cooperative relation with the shoulder 1 of the two armlever 2, so that the two arm lever 2 is free to be moved outwardly tothe dash line position as shown in Fig. 1, catching on the limitingshoulder of the latch 9 and thereby breaking contact between theconducting arm I and the conducting contact 6. To insure the arm 2catching on the limiting shoulder H the latch 8 is provided with alimiting tail piece 24 which contacts with the coil protecter l5 toprevent the right hand end of the latch 8, as viewed in Fig. 1, fromrising to such a height that the two arm lever 2 may pass beyond thelimiting shoulder I4 of the latch 9.

In order to insure the movement of the two arm lever 2 from the fullline position to the dash line position as shown in Fig. 1, applicantpreferably provides a bias. This bias, in the preferred form, is anexpansible member or compression spring 25, only one of which appears inthe drawing, positioned between lever 2 and spring abutments as 26,preferably formed integral with the protecting casing l5.

After lever 2 has moved into the dash line position, as shown in Fig. 1,it is returned to normal position in contact with contact member 6 by amanual movement. In order to facilitate this movement applicant prefersto provide a manipulating button 21. This manipulating button ispreferably made of insulating material and is attached to one arm of thetwo arm lever 2 in any suitable or appropriate manner as by screw 28.

The device hereinbefore described furnishes a rugged, substantial,easily manipulated and easily maintained circuit controller especiallysuitable for use in connection with heating circuits which aremanipulated by comparatively unskilled persons.

In Figure 4 applicant has schematically shown a preferred arrangement ofcircuits and apparatus for energizing and controlling a heating unit.

In Fig. 4 a source of operating and heating current is connected withthe wire 29 in which is interposed the manually operable switch 30 ofany desired form. When the switch 39 is closed, that is, makes contactwith the wire 3|, current may flow to and through the non-inductiveresistance 32, to the wire 33, relay coil 34, and wire to the conductingarm I and from conducting arm I through the two arm lever 2 and wire 36to the other side of the source of potential.

Current flowing in the above traced path energizes the relay coil 34 andso causes the armature 3'! to be raised so as to make contact with wire38. As soon as this contact is made between 31 and 38, current thenflows from the positive terminal of the source through wire 29, switch3| wires 3| and 38, armature 3'! and wire 39 to the several heatingcoils as and then to the negative terminal of the source.

Thermostat 4| is positioned so as to be influenced by the heat generatedby the heating coils Ail. When the temperature has arrived at a certainhigh value, the thermostat 4| will close its contacts 42 and 43 so thata shunt path is provided from the junction of resistance 32 and wire 33to the negative terminal of the source which so decreases the currentflow in current 34 that the armature 3'! is released, or drops to itslower position, as shown in Fig. 4, so cutting oil" the supply ofelectrical energy to the heating coils 40. When these coils and thespace heated thereby are sufliciently cool, the thermostat again opensits contacts 42 and 43, and, if switch 30 is closed, the coils are againsupplied with energy.

It might very well be that thermostat 4| would fail to act properly sothat a continuous supply of energy would be fed to the heating coils4|]; or a short circuit of some one of the coils might occur sending agreater amount of current through the other coils; or the vent for thespace being heated by the coils 4i! might be accidentally closed; or ablower motor blowing air over the coils 46 might become defective andstopped. This would either finally burn up the coils or cause adangerous rise of temperature in the space within which the coils aresituated. In order to provide for this, applicant provides a thermostat44 which is illustrated as being of the ordinary lei-metallic rod typewhich bends in one direction by decrease of temperature and in the otherby the increase of temperature. In Fig. 4 the thermostat 44 is shown inthe open position. If the temperature caused by the coils 4|] rises toohigh, that is, higher than would be necessary to cause thermostat 4| toclose its contacts, and thermostat 4| fails to close its contacts, thenthermostat 44 makes contact at its upper end, as shown in Fig. 4, withpost 45. The current could then flow from armature 31 through wire 46,noninductive resistance 41, wire 48, coil l6, wire 49, post 45,thermostat 44, and wire 5|] to the negative terminal of the source.Current flowing in the above traced path would energize coil I6 andcause armature 20 to be raised thereby raising latch rod 2| and liftinglatch 9 so that lever 2, by reason of springs, as 25, moves into aposition corresponding with the dash line position of Fig. 1, that is,so that conducting arm I breaks contact with contact point 6. As soon asand 6 separate, relay coil 34 becomes de-energized and armature 31 dropsand cuts off the supply of energy to the heating coils 40, therebyinsuring that they will not become unduly heated or burn out.

Even if the temperature falls to a proper value after thermostat 44 hasbroken the circuit at armature 31, the circuit will not bere-established at armature 31 until the button 21 has been manuallymanipulated to restore the conducting arm I to its cooperativeconnection with contact 6, so that if the circuit breaker is open due toa defect, it would not, of itself, again close the circuit so thatcurrent may be supplied to the heating coils, and at the same time theattention of the operator will be arrested both by the visible movementof button 21 and by the click of the resetting action of the switch,which thus yields an audible signal to the person operating the button21. The operator will thus be advised that the defect exists and musttake the necessary steps to rectify the same, as such repetitive actionwill occur as frequently as the button 21 is pushed in, so long as thedefective condition obtains in the circuit.

Applicants arrangement of heating and controlling circuits is simple,easy to maintain, and susceptible of use by one not highly skilled,furthermore, is particularly safe in that the controlling and governingdevices are simple and rugged and once automatically operated must bereturned to normal condition by a manual operation.

Although I have particularly described one particular physicalembodiment of my invention and explained the principle and operationthereof, nevertheless, I desire to have it understood that the formselected is merely illustrative but does not exhaust the possiblephysical embodiments of the idea of means underlying the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. In a heating arrangement, in combination: a heating coil; means forsupplying electrical energy to said coil including a relay armature;means for controlling the armature of the relay including an electromagnetic circuit breaker and a relay coil for said relay armature; athermostat including contacts bridged when the thermostat is exposed toone temperature and unbridged when the thermostat is exposed to anotherlow temperature, said contacts, when bridged, included in a shuntcircuit around said relay coil whereby the relay coil becomessuiiiciently de-energized to fail to control the armature whereby theheating coil circuit is open another thermostat, said thermostatarranged in a circuit, including the .electrormagnetic circuit breaker,in shunt to the heating coils, said last mentioned thermostat arrangedto close said last mentioned .circuit upon being exposed to above agiven temperature and to open the circuit when exposed to below the saidtemperature and means for manually closing the relay coil circuit afterbeing opened by the electro-magnetic circuit breaker, whereby when theelectro-magnetic circuit breaker is energized the relay coil circuit isbroken.

2. A heating arrangement including a heater circuit; electric heatingmeans in said circuit; a control circuit for said heater circuit; anelectromagnetic relay included in, and operated by, said controlcircuit, and adapted to establish and break said heating circuit;exclusively automatic means for operating said control circuit,comprising a thermostat; a secondary control circuit for said heatingcircuit comprising an electromagnetic circuit-breaker, and a secondthermostat co-operating therewith exclusively for breaking said heatercircuit; and an exclusively manually operable means for re-setting saidcircuitbreaker to re-establish said heater circuit.

3. A heating arrangement including a heater circuit; electric heatingmeans in said circuit; a control circuit for said heater circuit; anelectromagnetic relay included in, and operated by, said controlcircuit, and adapted to establish and break said heating circuit;exclusively automatic means for operating said control circuit,comprising a thermostat; a secondary control circuit for said heatingcircuit comprising an electro-magnetic circuit-breaker, and a secondthermostat co-operating therewith exclusively for breaking said heatercircuit; and an exclusively manually operable means for re-setting saidcircuitbreaker to re-establish said heater circuit, said second-namedthermostat being eilective independently of said first named thermostat.

4. A heating arrangement including a heater circuit; electric heatingmeans in said circuit; a control circuit for said heater circuit; anelectric switch comprising an armature and a relay coil included in, andoperated by, said control circuit, and adapted to establish and breaksaid heating circuit; a thermostat responsive to a given degree oftemperature, and serving as exclusively automatic means for operatingsaid control circuit; a secondary control circuit for said heatingcircuit, comprising an electro-magnetic circuit-breaker, and a secondthermostat effective independently of the other thermostat andco-operating with said circuit-breaker exclusively for breaking saidheater circuit; and an exclusively manually operable means for operatingsaid circuit-breaker to re-establish said heatercircuit.

5. A heating arrangement characterized by the elements combined andco-operating as set forth in claim 1, and further characterized byhaving said electro-magnetic circuit breaker and said second-namedthermostat so included in circuit with said relay coil that duringcontinued operation of said second-named thermostat, after any operationof the means for manually closing the relay circuit, saidelectro-magnetic circuit breaker will again break the relay coilcircuit, and at the same time cause a visible movement of said manuallyoperable means accompanied by an audible click or signal, both of whichare adapted to arrest the attention of the operator, repeatedly.

6. A heating arrangement characterized by the elements combined andco-operating as set forth in claim 3, and further characterized byhaving said electro-magnetic circuit breaker and said second-namedthermostat so included in circuit with said relay coil that uponcontinued existence in said heater-circuit of an abnormally heatedcondition after operation of said manually operable means, saidelectro-magnetic circuit breaker will again break the heater circuit,and at the same time cause a visible movement of said manually operablemeans and an audible click or signal both adapted to arrest theattention of the operator.

7. An electric heating system characterized by an electric heatercircuit including an electrially energizable heater and acircuit-closing switch therefor, a magnet controlling said switch, acircuit for said magnet shunting the heater, with a thermostat adjacentto the heater, and responsive to a predetermined degree of heat therein,which controls the said magnet, together with a second thermostatresponsive independently of said first-named thermostat to an excessivetemperature of the space to be heated and included in a control circuitwith said magnet and with a control device comprising a, pivotedelectrically conductive circuit-breaker arm in series with said magnet,and also comprising means to actuate said arm, a controlling means forsaid arm, a second electro-magnetic means to operate said armcontrollingmeans to open the circuit of the firstnamed magnet and therebyde-energize said heater, and means capable of exclusively manualactuation to move said arm to a position in which the circuit of thefirst-named magnet will be closed, and in which said control circuitwill again become efiective in response to said condition of overheat.

8. An electric heating system characterized by an electric heatercircuit including an electrical energizable heater and a circuit-closingswitch therefor, a magnet controlling said switch, a circuit for saidmagnet shunting the heater, with a thermostat adjacent to the heater,and responsive to a predetermined degree of heat therein, which controlsthe said magnet, together with a second thermostat responsiveindependently of said firstnamed thermostat to an excessive temperatureof the space to be heated and included in a control circuit with saidmagnet and with a control device comprislng a pivoted electricallyconductive circuit-breaker arm in series with said magnet, and alsocomprising means to bias said arm to circuit-breaking position, abias-controverting means capable of exclusively manual actuation to movesaid arm to a contact-making position in which the circuit of thefirst-named magnet will be closed, and whereby the dual control of saidfirst-named magnet by said control circuit and by said shunt will againbecome normally effective in response to said heat conditions; saidcontrol device having also a latch to hold said arm in saidcontact-making position, and another electro-magnetic means in serieswith said secondnamed thermostat and adapted to trip said latch when thesecond-named thermostat is closed.

9. An electric heating system characterized by an electric heatercircuit and a circuit closing switch therefor, a magnet controlling saidswitch, a circuit for said magnet shunting the heater; a circuitshunting said magnet and including a thermostat responsive to changes ofheat in the space to be heated and adapted to condition said magnetcircuit normally to control the operation of said heater circuit andthereby maintain a predetermined degree of heat in said space; saidsystem being further characterized by another relay circuit shuntingsaid heater circuit, and including a relay coil and another thermostaticdevice responsive to excessive heat from said electric heater; aciinnit-making-and-breaking device for said first-named magnet circuitand adapted to be operated by said relay shunt circuit, and means tobias said device to open the 10 same, thereby to ole-energize said firstnamed magnet and consequently to de-energize said heater; abias-controverting means exclusively operable by direct manual pressureto its biascontroverting position, thereby to close the magnet circuitand cause said heater to be energized and means operable by said relaycoil when energized by the closing of said second named thermostat, topermit said bias to become effective; whereby said heater will bede-energized.

ROBERT J. PARSONS.

